Having something appear on your face can be understandably distressing. However, it is difficult to guess what might be the cause of this lump without being able to visually inspect it myself. Also, I would want to ask you a few more detailed questions about the rash, such as whether it has changed in size or quality, if it is itchy or painful, etc. For these reasons, it would be best for you to see your primary care doctor
who would be able to better determine what might be going on. The red lump could be caused by a number of different things. You could have a pustular lesion of the face, or basically, a pimple. This pimple could have become bigger and deeper in size, and developed into an abscess
that would need to be opened and drained. You may have been bitten by an insect. Some bugs cause very characteristic looking rashes that would need further treatment. Lyme, for example, is caused by a bacteria carried by ticks and produces a bulls-eye looking rash (not in all cases). Depending on how the lump looks, a mass on the face could also be concerning for skin cancer. Basal and squamous cell cancers can present as reddish masses. Even melanoma, although usually darker black or brown in color, can have a red appearance. Please see your primary care doctor who can determine whether you may need a referral to a dermatologist
for further management.